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From: Andreas Schwab <schwab@suse.de>
To: Zishun Yi <vulab@iscas.ac.cn>
Cc: pjw@kernel.org,  palmer@dabbelt.com,  aou@eecs.berkeley.edu,
	linux-riscv@lists.infradead.org,  linux-kernel@vger.kernel.org,
	alex@ghiti.fr,  ajones@ventanamicro.com,  cleger@rivosinc.com,
	charlie@rivosinc.com,  namcao@linutronix.de
Subject: Re: [PATCH v2] riscv: misaligned: Restore epc in error path
Date: Mon, 11 May 2026 09:53:08 +0200	[thread overview]
Message-ID: <mvmh5oe1ixn.fsf@suse.de> (raw)
In-Reply-To: <20260509074053.1748061-1-vulab@iscas.ac.cn> (Zishun Yi's message of "Sat, 9 May 2026 15:40:53 +0800")

On Mai 09 2026, Zishun Yi wrote:

> diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c
> index 2a27d3ff4ac6..24f898853bba 100644
> --- a/arch/riscv/kernel/traps_misaligned.c
> +++ b/arch/riscv/kernel/traps_misaligned.c
> @@ -307,13 +307,17 @@ static int handle_scalar_misaligned_load(struct pt_regs *regs)
>  		return -1;
>  	}
>  
> -	if (!IS_ENABLED(CONFIG_FPU) && fp)
> +	if (!IS_ENABLED(CONFIG_FPU) && fp) {
> +		regs->epc = epc;
>  		return -EOPNOTSUPP;
> +	}
>  
>  	val.data_u64 = 0;
>  	if (user_mode(regs)) {
> -		if (copy_from_user(&val, (u8 __user *)addr, len))
> +		if (copy_from_user(&val, (u8 __user *)addr, len)) {
> +			regs->epc = epc;
>  			return -1;
> +		}
>  	} else {
>  		memcpy(&val, (u8 *)addr, len);
>  	}
> @@ -409,12 +413,16 @@ static int handle_scalar_misaligned_store(struct pt_regs *regs)
>  		return -1;
>  	}
>  
> -	if (!IS_ENABLED(CONFIG_FPU) && fp)
> +	if (!IS_ENABLED(CONFIG_FPU) && fp) {
> +		regs->epc = epc;
>  		return -EOPNOTSUPP;
> +	}
>  
>  	if (user_mode(regs)) {
> -		if (copy_to_user((u8 __user *)addr, &val, len))
> +		if (copy_to_user((u8 __user *)addr, &val, len)) {
> +			regs->epc = epc;
>  			return -1;
> +		}

I think this is better handled by a common error exit.

-- 
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."

WARNING: multiple messages have this Message-ID (diff)
From: Andreas Schwab <schwab@suse.de>
To: Zishun Yi <vulab@iscas.ac.cn>
Cc: pjw@kernel.org,  palmer@dabbelt.com,  aou@eecs.berkeley.edu,
	linux-riscv@lists.infradead.org,  linux-kernel@vger.kernel.org,
	alex@ghiti.fr,  ajones@ventanamicro.com,  cleger@rivosinc.com,
	charlie@rivosinc.com,  namcao@linutronix.de
Subject: Re: [PATCH v2] riscv: misaligned: Restore epc in error path
Date: Mon, 11 May 2026 09:53:08 +0200	[thread overview]
Message-ID: <mvmh5oe1ixn.fsf@suse.de> (raw)
In-Reply-To: <20260509074053.1748061-1-vulab@iscas.ac.cn> (Zishun Yi's message of "Sat, 9 May 2026 15:40:53 +0800")

On Mai 09 2026, Zishun Yi wrote:

> diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c
> index 2a27d3ff4ac6..24f898853bba 100644
> --- a/arch/riscv/kernel/traps_misaligned.c
> +++ b/arch/riscv/kernel/traps_misaligned.c
> @@ -307,13 +307,17 @@ static int handle_scalar_misaligned_load(struct pt_regs *regs)
>  		return -1;
>  	}
>  
> -	if (!IS_ENABLED(CONFIG_FPU) && fp)
> +	if (!IS_ENABLED(CONFIG_FPU) && fp) {
> +		regs->epc = epc;
>  		return -EOPNOTSUPP;
> +	}
>  
>  	val.data_u64 = 0;
>  	if (user_mode(regs)) {
> -		if (copy_from_user(&val, (u8 __user *)addr, len))
> +		if (copy_from_user(&val, (u8 __user *)addr, len)) {
> +			regs->epc = epc;
>  			return -1;
> +		}
>  	} else {
>  		memcpy(&val, (u8 *)addr, len);
>  	}
> @@ -409,12 +413,16 @@ static int handle_scalar_misaligned_store(struct pt_regs *regs)
>  		return -1;
>  	}
>  
> -	if (!IS_ENABLED(CONFIG_FPU) && fp)
> +	if (!IS_ENABLED(CONFIG_FPU) && fp) {
> +		regs->epc = epc;
>  		return -EOPNOTSUPP;
> +	}
>  
>  	if (user_mode(regs)) {
> -		if (copy_to_user((u8 __user *)addr, &val, len))
> +		if (copy_to_user((u8 __user *)addr, &val, len)) {
> +			regs->epc = epc;
>  			return -1;
> +		}

I think this is better handled by a common error exit.

-- 
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."

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linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

  reply	other threads:[~2026-05-11  7:53 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-09  7:40 [PATCH v2] riscv: misaligned: Restore epc in error path Zishun Yi
2026-05-09  7:40 ` Zishun Yi
2026-05-11  7:53 ` Andreas Schwab [this message]
2026-05-11  7:53   ` Andreas Schwab
2026-05-11 12:41   ` [PATCH v3] " Zishun Yi
2026-05-11 12:41     ` Zishun Yi
2026-05-13  2:13     ` Maciej W. Rozycki
2026-05-13  2:13       ` Maciej W. Rozycki

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